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Multi-Way Conventional loudspeakers with crossovers

KEF Q500 new crossover
KEF Q500 new crossover
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Old 5th April 2019, 11:56 AM   #11
wtnsmk is offline wtnsmk  United Kingdom
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Originally Posted by chris661 View Post
It doesn't look like the stock crossover is up to much. 1000uF in series with a PR alignment is crazy to me.

If you're near Sheffield, gimme a shout and we can do this properly, starting with some good measurements.

Chris
Ah that is really generous thank you, would be amazing, but I live in London without a car : \

However, I did some measurement (Scarlet 2i2, Rode NT1000, 50cm/20inch distance, facing the tweeter).
I only could do for the two inputs (IPL, IPH), not separately for all speakers.

Blue -> all three speakers
Green -> IPL with the LF/MF (5.25in alu Uni-Q, 5.25in alu)
Yellow -> IPH with the HF tweeter (1in vented alu dome).

Click the image to open in full size.

I know this is not too much, but this is what I could do so far without touch anything inside the cabinet.
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Old 5th April 2019, 04:33 PM   #12
wtnsmk is offline wtnsmk  United Kingdom
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One of the improvements in the KEF Q550 was the new crossover. Maybe the only one, but I only heard good things about it. Would be interesting to see the new crossover. Also the higher series like the "r" series and the "reference" crossovers.
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Old 5th April 2019, 06:54 PM   #13
Sonce is online now Sonce  Macedonia
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Originally Posted by Zvu View Post
I'd recommend making it a three way
This is a good advice!
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Old 5th April 2019, 07:56 PM   #14
wtnsmk is offline wtnsmk  United Kingdom
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I decided to do some proper measurement. So what you guys think about the Behringer ECM8000? I would use it with Focusrite scarlet 2i2.
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Old 5th April 2019, 09:08 PM   #15
ernperkins is offline ernperkins  United States
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The ECM8000 _used_ to be a good mic if you had a calibration file. But the quality of ECM8000s of late has spiraled downward. See this LINK for more.
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Old 5th April 2019, 09:52 PM   #16
wtnsmk is offline wtnsmk  United Kingdom
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Originally Posted by ernperkins View Post
The ECM8000 _used_ to be a good mic if you had a calibration file. But the quality of ECM8000s of late has spiraled downward. See this LINK for more.

Only for this project, invest 100+ just for measurement microphone, would be crazy IMO.
I found the ECM8000 for 26 (amazon). That is something what I think it's fine to pay for, and later on I could use it for other eg acoustic measurements.
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Old 8th April 2019, 10:31 PM   #17
wtnsmk is offline wtnsmk  United Kingdom
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Originally Posted by Zvu View Post
1.Measuring raw driver responses in factory cabinets at least 2.2m high in air outdoors 0-90 degrees.
2.Measuring woofer TS parameters.
3.Deriving parameters of passive radiators used so i can model the response.
1. So you mean measure frequency response with a calibrated microphone to each speaker without crossover?
2. Not sure what TS parameters mean and how to measure them. Could you please provide some information?
3. How can I do this?

Also don't I need an impedance graph?
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Old 9th April 2019, 04:13 PM   #18
Zvu is offline Zvu  Serbia
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Originally Posted by wtnsmk View Post
1. So you mean measure frequency response with a calibrated microphone to each speaker without crossover?
2. Not sure what TS parameters mean and how to measure them. Could you please provide some information?
3. How can I do this?

Also don't I need an impedance graph?
1. Yes, like explained here: http://techtalk.parts-express.com/fi...tch?id=1149302 or use ARTA and VituixCAD like explained here: Software

2. You measure it with DATSv2 like explained here: YouTube TS parameters are derived from impedance graph by the DATS software.

3. First measure your woofer imedance response and frequency response nearfield in cabinet with passive radiators. Then you measure Sd of passives and presume Xmax (not so important here). Then you play a little with Fsp, Qmp and Mmp in simulator until you get measured woofer response or the most similar version of it.

Last edited by Zvu; 9th April 2019 at 04:16 PM.
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Old 10th April 2019, 08:33 PM   #19
wtnsmk is offline wtnsmk  United Kingdom
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Originally Posted by Zvu View Post
1. Yes, like explained here: http://techtalk.parts-express.com/fi...tch?id=1149302 or use ARTA and VituixCAD like explained here: Software

2. You measure it with DATSv2 like explained here: YouTube TS parameters are derived from impedance graph by the DATS software.

3. First measure your woofer imedance response and frequency response nearfield in cabinet with passive radiators. Then you measure Sd of passives and presume Xmax (not so important here). Then you play a little with Fsp, Qmp and Mmp in simulator until you get measured woofer response or the most similar version of it.
Thanks! Can I do the TS measurements in the cabinet as well?
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Old 10th April 2019, 09:10 PM   #20
wtnsmk is offline wtnsmk  United Kingdom
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Originally Posted by Zvu View Post
1. Yes, like explained here: http://techtalk.parts-express.com/fi...tch?id=1149302 or use ARTA and VituixCAD like explained here: Software

2. You measure it with DATSv2 like explained here: YouTube TS parameters are derived from impedance graph by the DATS software.

3. First measure your woofer imedance response and frequency response nearfield in cabinet with passive radiators. Then you measure Sd of passives and presume Xmax (not so important here). Then you play a little with Fsp, Qmp and Mmp in simulator until you get measured woofer response or the most similar version of it.
So I'm getting the DATSv2 for couple of weeks tomorrow.
Do I have to take out the speakers from the cabinet, or it doesn't matter? I couldn't find any information about it.
The other think what I can't find is could I measure the impedance graph on each driver including the tweeter? I only saw people using it on larger speakers.

I'm planning to do all the necessary DATS measurement tomorrow so I don't have to touch my speakers again for a while.

What I'm planning to do is
1. Screw down the back plate
2. Unsolder the drivers wires from the crossover
3. Clip the probes to the wires at the bottom of cabinet - wouldn't this be an issue because I would measure the wires too?
4. Run the measurement on the back of the speaker on LF woofer (without and with added mass)
5. Run the measurement on the back of the speaker on MF driver (without and maybe with added mass)
6. Run the measurement on the back of the speaker on HF tweeter (only without mass, as I can't and don't want to put anything onto that membrane)
7. Solder back the wires and close back the driver
8. Export the data and open a beer

Would this be a correct measurement?
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